Does the script fail silently, or do you get an error message? And if it fails silently, do you suppose you might be able to add some error checking to the script so that it will complain if something goes wrong? You're going to need to uncover and report to us some clues before anyone can meaningfully help you to ascertain what's wrong.

Also, is there any way you can post relevant portions of the code, or at least a small example script that replicates the failure? Otherwise, we're only going to be able to guess, and you don't really want to settle for guesses when by providing a little more background you could get accurate answers.

#!usr/bin/perl
while(<>)
{
 if (/ (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) 
+(\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w)
+ (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w) (\w\w
+) (\w\w) (\w\w) (\w\w) (\w\w)/)
{
  if ($2=="11")
  {
 print "\tBSC -> BTS\tBCCH INFOmation ", $1,$2,$3,$4,$5,$6,$7,$8,$9,$1
+0,$11,$12,$13,$14,$15,$16,$17,$18, $19,$20,$21,$22,$23,$24,$25,$26,$2
+7,$28,$29,$30,"\n";
 print "\tMessage discriminator   :",$1,"\n";
 print "\tMessage type            :",$2,"\n";
 print "channel number :";
 print "\tchannel number :",$3,$4,"\n";
 print "\tElement Identifier      :",$14,"\n";
print "system info Type        :",$7,$8,"\n";
print "\tElement Identifier      :" ,$7,"\n";
print "\tsystem info Type        :", $8,"\n";
print "Full BCCH Info   :",$7,$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,$1
+8,$19,$20,$21,$22,$23,$24,$25,$26,$27,$28,$29,$30,"\n";
  }
 elsif ($2=="34")
  {
  print "\tBSC -> BTS\tSACCH INFO MODIFY ", $1,$2,$3,$4,$5,$6,$7,$8,$9
+,$10,$11,$12,$13,$14,$15,$16,$17,$18,               $19,$20,$21,$22,$
+23,$24,$25,$26,$27,$28,$29,$30,"\n";
  print "\tMessage discriminator   :",$1,"\n";
  print "\t Message type            :",$2,"\n";
  print "channel number :";
  print "\tchannel number :",$3,$4,"\n";
print "system info Type        :",$7,$8,"\n";
print "\tElement Identifier      :",$7,"\n";
print "\tsystem information         :",$8,"\n";
print "L3 INFORMATION  :",$7,$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,$18
+,$19,$20,$21,$22,$23,$24,$25,$26,$27,$28,$29,$30,"\n";
  }
 elsif ($2=="13")
{
 print "\tBSC -> BTS\tCHAN_RQD ", $1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$
+12,$13,$14,$15,$16,$17,$18,$19,$20,$21,"\n";
  print "\tMessage discriminator   :",$1,"\n";
  print "\t Message type            :",$2,"\n";
  print "channel number :";
  print "\tchannel number :",$3,$4,"\n";
print "\t Identifier      :",$3,"\n";
print "\tRequest Reference :",$5,$6,$7,$8,"\n";
print "\tElement Identifier      :",$5,"\n";
print "\tRandom access information :",$6,"\n";
print "\tFrame number modulo :",$7 ,$19,"\n";
print  "Access delay :",$9,$10,"\n";
print "\tElement indentifier :",$9,"\n";
print  "\tAccess delay :",$10,"\n";
}
elsif ($2 =="33")
 {
print "\t BTS -BSC\tRF_CHAN_REL_ACK   : ",$1,$2,$3,$4,"\n";
print "BTSM Header : ";
print "\tmesssage Discriminator :", $1,"\n";
print "\tMessage Type :\t", $2,"\n";
print "channel number :";
print "\tchannel number :",$3,$4,"\n";
print "\tElement indentifier :",$3,"\n";
}
elsif ($2=="22")
{
print "\tBSC -> BTS\tCHAN_ACTIV_ACK   : " ,  $1 , $2, $3 , $4 , $5 , $
+6 , $7, "\n";
print "BTSM Header : ";
print "\t;messsage Discriminator :" , $1,"\n";
print "\tMessage Type : \t", $2,"\n";
print "channel number :";
print "\tchannel number : ", $3 , $4,"\n";
print "\tElement indentifier :",$3,"\n";
print "\tFrame number :" ,$5, $6 , $7,"\n";
print "\tElement indentifier :" , $5, "\n";
}
elsif ($2=="21")
{
print "\tBSC -> BTS\tCHAN_ACTIV  :",$1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11
+,$12,$13,$14,"\n";
print "BTSM Header : ";
print "\tmesssage Discriminator :",$1,"\n";
print "\tMessage Type :\t",$2,"\n";
print "channel number :";
print "\tchannel number :",$3,$4,"\n";
print "\tElement indentifier :",$3,"\n";
print "\tActivation type :",$5,$6,"\n";
print "\tElement indentifier :",$5,"\n";
print "\tChannel mode :",$7,$8,$9,$10,$11,$12,"\n";
print "\tElement indentifier :",$17,"\n";
print "\tLength :",$18,"\n";
print "\tTiming Advance :" ,$13,$14,"\n";
print "\tElement indentifier :",$13,"\n";
}
}
}
[download]

20061226 Janitored by Corion: Added code tags, as per Writeup Formatting Tips

To avoid puzzling problems with missing data files, test your input with something along these lines:

#!/usr/bin/perl
if (!defined $ARGV[0]) { # make sure some input is given
   die "No input file provided: $!";
} elsif (!-f $ARGV[0]) { # input is not a file
   die "Input $ARGV[0] not available as a file";
}
[download]

Then you'll know when you've got no data file to work on.

Also suggested is the use of "use warnings" and "use strict" at the beginning of nearly every Perl program.

non-Perl: Andy Ford

print STDERR "Well, I made it to line: ", __LINE__, ".\n";
[download]

If not, debug that. If so, uncomment a small block of code and copy your debug statement just below it. Run your test again.

Feel free to comment out debug statements earlier in the script, if they have told you what they need to. But don't delete them, As your script matures, they may get reworked as log statements and be used again.

As you copy your debug line down past tested and working code, you can make the debug output more informative, say by writing it this way:

print STDERR "At line: ", __LINE__, ", the message type is $2, so we'l
+l append to the log.\n";
etc. . . .
[download]

You would likely learn quite a bit about your script were you to write conditions to handle exceptions. Robust code includes lots of conditional paths that the programmer expects will never be taken by legitimate data in a production environment. But coding that exception handling will help you see where you perhaps made bad assumptions about what your code is actually doing. A properly handled exception might recover so the script need not terminate. It could add useful debugging information to a log file. At the very least it could die in a loud and descriptive way.

-- Hugh